A flaw in the system leaves physicists grappling with dimensionless units. Water is a precious resource. So protest erupted when, last September, India’s Supreme Court ordered Karnataka state to ...

In addition to other scientific units, the kilogram also is now defined by a natural constant. This is made possible by single crystals grown from highly enriched silicon-28. In addition to Ampere, ...

For the first time in more than 30 years, new terms have been officially added to the International System of Units (SI). The four new prefixes – ronna, quetta, ronto and quecto – describe very large ...

All change: work on the redefinition of the kilogram was carried out using a Kibble balance. (Courtesy: BIPM) The redefinition of four units of the International System of Units (SI) will come into ...

Meet the metric system’s newest prefixes: ronna-, quetta-, ronto- and quecto-. Science News spoke with Richard Brown, head of metrology at the National Physical Laboratory in Teddington, England, ...

It doesn’t happen too often, but after a vote that took place earlier today near Paris, science textbooks really will have to be rewritten. At the Congress Chamber in the Palace of Versailles, ...

The United States's version of the Imperial system is based on an older British version. MaxPixel At press time, only three of the world's countries don't use the metric system: the United States, ...

A hidden world of quantum metrologists ensure that everyday devices perform safely and correctly, but their work is never ...

The kilogram — anywhere in the world, for any purpose — is based on the exact weight of a golf-ball-sized chunk of platinum and iridium stored under three glass bell jars in a vault in an ornate ...